DOCSLIB.ORG

Structural Geology of the Gass Peak Area Las Vegas Range, Nevada

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Structural Geology of the Gass Peak Area Las Vegas Range, Nevada RICE UNIVERSITY STRUCTURAL GEOLOGY OF THE GASS PEAK AREA LAS VEGAS RANGE, NEVADA by WILLIAM JAMES EBANKS, JR. A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ARTS 3 1272 00020 4303 Thesis Director's Signature Houston, Tex.z (May, 1965) Abstract A field-mapping study of the area around Gass Peak, Las Vegas Range, Clark County, Nevada, has demonstrated the presence of a thick sequence of Paleozoic and Precambrian rocks overthrust on younger, Upper Paleozoic beds along the Gass Peak Thrust. Formations recognized in the upper plate of the thrust are the Precambrian Stirling Quartzite, the Precambrian and Cambrian Wood Canyon Formation, the Cambrian, Carrara, Bonanza King, and Nopah Formations, and the Ordovician lowermost Pogonip Group. Rocks in the lower plate are the Devonian Sultan Limestone, Mississippian Monte Cristo Lime¬ stone, and the Permo-Carboniferous Bird Spring Formation. The Miocene Horse Spring Formation unconformably overlies the Paleozoic rocks. Faulting on the Gass Peak Thrust resulted in approxi¬ mately 18,000 feet of stratigraphic displacement from west- to-east. Several large folds and many high-angle reverse faults are associated with the thrust fault. All of these features, the major thrust and smaller re¬ lated structures, have been rotated westward through 90 de¬ grees by right-lateral strike-slip movement on the adjacent Las Vegas Valley Shear Zone. The "drag" structure and a unique set of faults in the Gass Peak area are related to east-west extension and north-south compression caused by i the rotation. i Strata above and below the Gass Peak Thrust are similar to strata in the Wheeler Pass Thrust, suggesting the two thrusts are offset equivalents. This implies more than 25 miles of relative horizontal shift between the two faults. Many details of structure are dissimilar between the Wheeler Pass and Gass Peak Thrusts, and if they were once the same feature, they have developed independently after being separ¬ ated. Structural evidence indicated that displacement on the Gass Peak Thrust occurred before movement along the Las Vegas Valley Shear Zone. There is little evidence in the mapped area for Tertiary block faulting. TABLE OF CONTENTS page no# I, INTRODUCTION . 1 A. PURPOSE OF INVESTIGATION 1 B. ACKNOWLEDGEMENTS ...... „. 1 C o PREVIOUS WORK oe..,oo,a.oo,.*«o,ooooa 2 II, LOCATION AND DESCRIPTION OF THE STUDY AREA 3 III, STRATIGRAPHY •,»oo»,,o«o*«,,oaeo, 3 A. METHODS ........... 5 B. GENERAL 5 C. FORMATIONS PRESENT .,... 7 1, Precambrian rocks 7 a. Stirling Quartzite 7 2• Cambrian rocks 8 a. Wood Canyon Formation 8 b. Carrara Formation .. 9 c. Bonanza King Formation •. 0 •.... 10 d. Nopah Formation •. 11 3, Ordovician rocks ................, 13 a, Pogonip Group 13 4, Devonian-Mississippian rocks (undifferentiated) 14 a, Monte Cristo Limestone and Sultan Limestone ...... 14 5, Mississippian-Pennsylvanian- Permian rocks ..o.. 14 a. Bird Spring Formation 14 6, Tertiary rocks 16 a. Horse Spring Formation ... 16 7, Quaternary rocks •»••«,«.. 19 a. Older and younger alluvium ,,,, 19 IV, STRUCTURAL GEOLOGY ,««o,oo,,20 A, REGIONAL SETTING 20 B. STRUCTURAL FEATURES OF THE GASS PEAK AREA ,e,0o,,,,,ea,e,,,,o,,,a*oeooooo, 21 U Gass Peak Thrust 21 a. General ,., 21 b. Stratigraphic displacement 22 c. Geometry o,*«,23 ii d. Footwall 23 e. Hanging wall 24 f. Decollement faulting 26 g. Other features 27 2» Structures related to thrusting • • 30 a. General .... ...... 30 b. Footwall features ... 30 Cl) Broad folds 30 (2) Reverse faults ...a........ 30 (3) Overturned folds 31 (4) Normal faults 33 c. Hanging wall features 37 (1) High-angle reverse faults • 37 (2) Broad folds 38 3. Structures related to the Las Vegas Valley Shear Zone 38 a. General ... 38 b. Extension faults 39 c. Back thrusts 41 4. Normal faulting 43 5. Late Tertiary deformation ...»..*• 44 6. Gravity sliding 44 C. TIMES OF MAJOR DEFORMATIONS 46 1. Thrust faulting 46 2. Strike-slip faulting 47 V. SUMMARY 48 VI. CONCLUSIONS 50 VII. BIBLIOGRAPHY 53 LIST OF ILLUSTRATIONS Figure 1 Index map of U.S.G.S. Quadrangles in the area of Las Vegas, Nevada . 4 Figure 2 Stratigraphic units of the Gass Peak area, Nevada «...o.• ••«..«..«......o.. 6 Figure 3 Major structural features near the • Gass Peak area, Nevada 18 Figure 4 Drag structures .......o«.o*.«o...... 40 Figure 5 Small-scale folding in the Bird Spring Formation ...................e. 25/ r 1 iii Figure 6 Overturned beds south of Dry Wash ... 32 Figure 7 Overturned beds south of Broken Hill 34 Figure 8 Normal fault dipping southward 35 Figure 9 Low-angle normal faults dipping northward 36 PLATE I Geologic Map of part of the Gass Peak Quadrangle, Clark County, Nevada •••• pocket - • I I 1. INTRODUCTION PURPOSE OF INVESTIGATION This study was undertaken to describe the structural geology in the area at the southern end of the Gass Peak Thrust, in the Las Vegas Range, Nevada. A more specific goal was the observation of structural features that might confirm or reject the postulated presence of a major strike- slip fault zone in the adjacent Las Vegas Valley. Of secondary interest, but significant to the interpretation of the geology of this complex area, was recognition of the stratigraphic units present in the mapped area. ACKNOWLEDGEMENTS / This geologist wishes to express his appreciation to the several persons whose help and criticism contributed to the completion of this thesis. First among these is Dr. B. C« Burchfiel, whose guidance in the field and super¬ vision were a valuable experience. Dr. J. Cl. De Bremaecker and Dr. R. R. Lankford also offered constructive criticism in discussions and in editing this thesis. Dr. J. L. Wilson, of Shell Development Company, kindly offered expert opinion on several Cambrian fossil identifications. The subject area is mostly within the U.S, Fish & Itfild- life Service, Desert Game Range, near Las Vegas, Nevada. The Manager of this refuge granted the writer complete freedom of access to that area. For the kind help and warm hospitality of the good people at the Corn Creek Field Station, the writer I .. is especially grateful. 2 Financial support of the writer was provided by a National Defense Education Act Fellowship. The Rice Uni¬ versity Geology Department provided field expense assistance. PREVIOUS WORK The expedition led by J. E. Spurr (1903) to explore the geology of Nevada south of the Fortieth Parallel was the first party of geologists to enter and report on the Gass Peak area. Spurr himself passed across the north end of the Las Vegas Range, but R. B. Rowe, discoverer of the Keystone Thrust, traveled the Mormon Wells Road, through the Gass Peak area, down to Las Vegas Valley. The text and map of Spurr's report indicate a slightly different topographic nomenclature than is presently used. The "Gass" or "Sheep Mountain" of that time is today called Gass Peak. Spurr's usage of "Las Vegas Range" and "New Mountains" have also been changed. Nevertheless, from Spurr's writing, it is clear that he recognized the change in strike of the formations from north- south to east-west at the south end of the Las Vegas Range. Spurr's suggestion that the "main fold of the Las Vegas Range,..., runs across the Las Vegas Valley and is probably to be found in the Spring Mountain Range on the other side...," is not acceptable in our present knowledge. Rowe's observations of stratigraphy and faulting are fairly accurate. F. C. Lincoln (1923) mentioned the Gass Peak Mining District in his early summary of mining operations of Nevada. From the most important mine, presently known as the Jung Bug Mine, zinc, gold, and silver ore was produced until abandon¬ ment in 1917. 3. C. R. Longwell, in his careful reconnaissance mapping of the one-degree Las Vegas quadrangle, covered the Gass Peak quadrangle and accurately reported the main features of the area on the map by Bowyer, Pampeyan, and Longwell (1958), Several other papers by Longwell on the Las Vegas and ad¬ jacent areas have been published (see references). Longwell (1960) first suggested the presence of the Las Vegas Valley Shear Zone and made numerous other observations and comments in the literature that have been of great assistance to this writer. Southern Nevada geology has profited greatly under his study. LOCATION AND DESCRIPTION OF THE STUDY AREA The north half of the U.S.G.S. "Gass Peak" fifteen- minute quadrangle (Figure 1) was mapped during two months of field work in the summer of 1964. Gass Peak (V.A.B.M. 6943), the dominant topographic feature of the quadrangle (Plate I), is 15 miles north of Las Vegas, Clark County, Nevada. Maximum relief encountered is about 4000 feet. Elevations range from 3000 feet to 7000 feet, but only 1000 to 2000 feet of relief is present locally. The climate is dry, desertic, with temperatures often exceeding 100°F. in the summer and precipitation averaging 4 to 6 inches, annually. Vegetation is sparse in most of the area and ecologic zonation ranges from the Creosote Bush to the transition between the Joshua Tree and Pinon- Juniper floral zones. Several fresh water springs are present 4 5 in the area, but most were dry at the time of study, and those still active were contaminated by alkali saltso STRATIGRAPHY METHODS Because the emphasis in this study is on structural geology, detailed description of the lithologic units recog¬ nized was not attempted* The writer briefly described units in the field, for comparison along strike, and hurriedly measured some of ttTe Precambrian and Lower Cambrian units, to compare thicknesses with other outcrops nearby* Dr* B* C. Burchfiel identified the various rock units in the mapped area while accompanying the writer on reconnaiss¬ ance* Some of the units are incomplete and change thickness drastically along strike, apparently because of "tectonic thinning", or replacement and omission of beds by faults within the formations* It remains to be determined whether the stratigraphic section is more complete farther north • .
Load more

Recommended publications
  • Discovery of Bilaterian-Type Through-Guts in Cloudinomorphs from the Terminal Ediacaran Period
    ARTICLE https://doi.org/10.1038/s41467-019-13882-z OPEN Discovery of bilaterian-type through-guts in cloudinomorphs from the terminal Ediacaran Period James D. Schiffbauer 1,2*, Tara Selly 1,2*, Sarah M. Jacquet 1, Rachel A. Merz3, Lyle L. Nelson4, Michael A. Strange5, Yaoping Cai6 & Emily F. Smith 4 The fossil record of the terminal Ediacaran Period is typified by the iconic index fossil Cloudina and its relatives. These tube-dwellers are presumed to be primitive metazoans, but resolving 1234567890():,; their phylogenetic identity has remained a point of contention. The root of the problem is a lack of diagnostic features; that is, phylogenetic interpretations have largely centered on the only available source of information—their external tubes. Here, using tomographic analyses of fossils from the Wood Canyon Formation (Nevada, USA), we report evidence of recog- nizable soft tissues within their external tubes. Although alternative interpretations are plausible, these internal cylindrical structures may be most appropriately interpreted as digestive tracts, which would be, to date, the earliest-known occurrence of such features in the fossil record. If this interpretation is correct, their nature as one-way through-guts not only provides evidence for establishing these fossils as definitive bilaterians but also has implications for the long-debated phylogenetic position of the broader cloudinomorphs. 1 Department of Geological Sciences, University of Missouri, Columbia, MO 65211, USA. 2 X-ray Microanalysis Core, University of Missouri, Columbia, MO 65211, USA. 3 Biology Department, Swarthmore College, Swarthmore, PA 19081, USA. 4 Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA.
    [Show full text]
  • Geodesy and Contemporary Strain in the Yucca Mountain Region, Nevada
    Geodesy and Contemporary Strain in the Yucca Mountain Region, Nevada By W.R. Keefer, J.A. Coe, S.K. Pezzopane, anofW. Clay Hunter U.S. GEOLOGICAL SURVEY Open-File Report 97-383 Prepared in cooperation with the NEVADA OPERATIONS OFFICE U.S. DEPARTMENT OF ENERGY (Interagency Agreement DE-AI08-92NV10874) Denver, Colorado 1997 U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Gordon P. Eaton, Director The use of firm, trade, and brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. For additional information write to: Copies of this report can be purchased from: Chief, Earth Science Investigations Program U.S. Geological Survey Yucca Mountain Project Branch Information Services U.S. Geological Survey Box 25286 Box 25046, Mail Stop 421 Federal Center Denver Federal Center Denver, CO 80225 Denver, CO 80225-0046 CONTENTS Abstract................................................................................................................................................................................. 1 Introduction .............................................................................. 1 Background and Piirpose...........................................................................................................................................^ 1 Geologic Setting ......................................................................................................................................................... 4 Geodetic
    [Show full text]
  • Tectonic Influences on the Spatial and Temporal Evolution of the Walker Lane: an Incipient Transform Fault Along the Evolving Pacific – North American Plate Boundary
    Arizona Geological Society Digest 22 2008 Tectonic influences on the spatial and temporal evolution of the Walker Lane: An incipient transform fault along the evolving Pacific – North American plate boundary James E. Faulds and Christopher D. Henry Nevada Bureau of Mines and Geology, University of Nevada, Reno, Nevada, 89557, USA ABSTRACT Since ~30 Ma, western North America has been evolving from an Andean type mar- gin to a dextral transform boundary. Transform growth has been marked by retreat of magmatic arcs, gravitational collapse of orogenic highlands, and periodic inland steps of the San Andreas fault system. In the western Great Basin, a system of dextral faults, known as the Walker Lane (WL) in the north and eastern California shear zone (ECSZ) in the south, currently accommodates ~20% of the Pacific – North America dextral motion. In contrast to the continuous 1100-km-long San Andreas system, discontinuous dextral faults with relatively short lengths (<10-250 km) characterize the WL-ECSZ. Cumulative dextral displacement across the WL-ECSZ generally decreases northward from ≥60 km in southern and east-central California, to ~25 km in northwest Nevada, to negligible in northeast California. GPS geodetic strain rates average ~10 mm/yr across the WL-ECSZ in the western Great Basin but are much less in the eastern WL near Las Vegas (<2 mm/ yr) and along the northwest terminus in northeast California (~2.5 mm/yr). The spatial and temporal evolution of the WL-ECSZ is closely linked to major plate boundary events along the San Andreas fault system. For example, the early Miocene elimination of microplates along the southern California coast, southward steps in the Rivera triple junction at 19-16 Ma and 13 Ma, and an increase in relative plate motions ~12 Ma collectively induced the first major episode of deformation in the WL-ECSZ, which began ~13 Ma along the N60°W-trending Las Vegas Valley shear zone.
    [Show full text]
  • Mule Deer and Antelope Staff Specialist Peregrine Wolff, Wildlife Health Specialist
    STATE OF NEVADA Steve Sisolak, Governor DEPARTMENT OF WILDLIFE Tony Wasley, Director GAME DIVISION Brian F. Wakeling, Chief Mike Cox, Bighorn Sheep and Mountain Goat Staff Specialist Pat Jackson, Predator Management Staff Specialist Cody McKee, Elk Staff Biologist Cody Schroeder, Mule Deer and Antelope Staff Specialist Peregrine Wolff, Wildlife Health Specialist Western Region Southern Region Eastern Region Regional Supervisors Mike Scott Steve Kimble Tom Donham Big Game Biologists Chris Hampson Joe Bennett Travis Allen Carl Lackey Pat Cummings Clint Garrett Kyle Neill Cooper Munson Sarah Hale Ed Partee Kari Huebner Jason Salisbury Matt Jeffress Kody Menghini Tyler Nall Scott Roberts This publication will be made available in an alternative format upon request. Nevada Department of Wildlife receives funding through the Federal Aid in Wildlife Restoration. Federal Laws prohibit discrimination on the basis of race, color, national origin, age, sex, or disability. If you believe you’ve been discriminated against in any NDOW program, activity, or facility, please write to the following: Diversity Program Manager or Director U.S. Fish and Wildlife Service Nevada Department of Wildlife 4401 North Fairfax Drive, Mailstop: 7072-43 6980 Sierra Center Parkway, Suite 120 Arlington, VA 22203 Reno, Nevada 8911-2237 Individuals with hearing impairments may contact the Department via telecommunications device at our Headquarters at 775-688-1500 via a text telephone (TTY) telecommunications device by first calling the State of Nevada Relay Operator at 1-800-326-6868. NEVADA DEPARTMENT OF WILDLIFE 2018-2019 BIG GAME STATUS This program is supported by Federal financial assistance titled “Statewide Game Management” submitted to the U.S.
    [Show full text]
  • 1 Running Head: SEQUENCE STRATIGRAPHY of TEXAS
    Running Head: SEQUENCE STRATIGRAPHY OF TEXAS MIDDLE PERMIAN PLATFORM CARBONATES OUTCROP-BASED CHARACTERiZATION OF LEONARDIAN PLATFORM CARBONATE IN WEST TEXAS: IMPLICATIONS FOR SEQUENCE STRATIGRAPHIC STYLES IN TRANSITIONAL ICEHOUSE-GREENHOUSE SETTINGS Stephen C. Ruppel, W. Bruce Ward1, and Eduardo E. Ariza Bureau of Economic Geology The University of Texas at Austin 1 Current address: Earthworks LLC, P.O. Box 178, Newtown, CT 06470-0178 1 ABSTRACT The Sierra Diablo Mountains of West Texas contain world class exposures of lower and middle Permian platform carbonates. As such these outcrops offer key insights into the products of carbonate deposition in the transitional icehouse/greenhouse setting of the early-mid Permian that are available in few other places in the world. They also afford an excellent basis for examing how styles of facies and sequence development vary between platform tops and platform margins. Using outcrop data and observations from over 2 mi (3 km) of continuous exposure, we collected detailed data on the facies composition and architecture of high frequency (cycle-scale) and intermediate frequency (high frequency sequence scale) successions within the Leonardian. We used these data to define facies stacking patterns along depositional dip across the platform in both low and high accommodation settings and to document how these patterns vary systematically between and within sequences . These data not only provide a basis for interpreting similar Leonardian platform successions from less well constrained outcrop and subsurface data sets but also point out some important caveats that should be considered serve as an important model for understanding depositional processes during the is part of the Permian worldwide.
    [Show full text]
  • U.S. Department of the Interior Bureau of Land Management
    U.S. Department of the Interior Bureau of Land Management Final Environmental Assessment DOI-BLM-NV0S010-2009-1014-EA May 2016 Eastern Nevada Transmission Project APPLICANT Silver State Energy Association GENERAL LOCATION Clark County, Nevada BLM CASE FILE SERIAL NUMBER N-086357 PREPARING OFFICE U.S. Department of the Interior Bureau of Land Management Las Vegas Field Office 4701 N. Torrey Pines Drive Las Vegas, NV 89130 Phone: (702) 515-5172 Fax: (702) 515-5010 This page intentionally left blank. Table of Contents Chapter 1 - Purpose and Need ...................................................................................................1 1.1 Introduction ....................................................................................................................1 1.2 Project Background ........................................................................................................1 1.3 Purpose and Need for Action .........................................................................................2 1.4 Decisions to be Made .....................................................................................................7 1.5 BLM Policies, Plans, Authorizing Actions, and Permit Requirements .........................7 Chapter 2 - Proposed Action and Alternatives ........................................................................9 2.1 Introduction ....................................................................................................................9 2.1.1 Regulatory Framework for Alternatives
    [Show full text]
  • Oligocene and Miocene), in Southern Nevada and Northwest Arizona D.G
    New K-Ar age determinations from syntectonic deposits (Oligocene and Miocene), in southern Nevada and northwest Arizona D.G. Carpenter and J.G. Carpenter Isochron/West, Bulletin of Isotopic Geochronology, v. 55, pp. 10-12 Downloaded from: https://geoinfo.nmt.edu/publications/periodicals/isochronwest/home.cfml?Issue=55 Isochron/West was published at irregular intervals from 1971 to 1996. The journal was patterned after the journal Radiocarbon and covered isotopic age-dating (except carbon-14) on rocks and minerals from the Western Hemisphere. Initially, the geographic scope of papers was restricted to the western half of the United States, but was later expanded. The journal was sponsored and staffed by the New Mexico Bureau of Mines (now Geology) & Mineral Resources and the Nevada Bureau of Mines & Geology. All back-issue papers are available for free: https://geoinfo.nmt.edu/publications/periodicals/isochronwest This page is intentionally left blank to maintain order of facing pages. 10 NEW K-Ar AGE DETERMINATIONS FROM SYNTECTONIC DEPOSITS (OLIGOCENE AND MIOCENE), IN SOUTHERN NEVADA AND NORTHWEST ARIZONA DANIEL G. CARPENTER Department of Geology, Oregon State University, Corvaiiis, OR 97331-5506 JAMES G. CARPENTER Present address: Mobii Exploration and Producing U.S. inc., 1225 17th Street, Denver, CO 80202 Four new K-Ar age determinations were obtained on plagioclase, rare K-feldspar, quartz and biotite shards, and Cenozoic syntectonic deposits that are important to struc rare lithic fragments in a partially devitrified groundmass. tural and stratigraphic investigations in the southern These beds Me up section from the basal limestone and Nevada, southwest Utah, and northwest Arizona region.
    [Show full text]
  • Mercury Bowling Alley Demolition
    MEMORANDUM OF AGREEMENT BETWEEN THE U.S. DEPARTMENT OF ENERGY NATIONAL NUCLEAR SECURITY ADMINISTRATION NEVADA FIELD OFFICE, AND THE NEVADA STATE HISTORIC PRESERVATION OFFICER REGARDING THE DEMOLITION OF THE MERCURY BOWLING ALLEY, NEVADA NATIONAL SECURITY SITE, NEVADA WHEREAS, the National Nuclear Security Administration Nevada Field Office (NNSA/NFO) intends to demolish the Mercury Bowling Alley (Building 23-517) on the Nevada National Security Site (NNSS) in Nye County, Nevada, as part of its plans for new construction and modernization of Mercury to support the NNSS's changing role in national security; and WHEREAS, the present undertaking consists of the demolition of Building 23-517 (SHPO Resource Number B 14451) that has remained vacant since the mid-i 990s following the end of nuclear testing activities at the NNSS (formerly Nevada Test Site [NTS]). In planning for the undertaking, NNSA/NFO considered all possible alternatives to avoid and minimize adverse effects to historic properties; and WHEREAS, theNNSA/NFO has defined the undertaking's area of potential effect (APE) as a 4.5-acre area in Mercury bounded on the west by the Mercury Highway, on the east by Teapot Street, on the south by Trinity Avenue, and on the north by a prominent terrace immediately south of a parking lot, park, and tennis/basketbatl court (Attachment A); and WHEREAS, the NNSA/NFO recorded and evaluated Building 23-517 (Attachment A) En accordance with the Nevada ArchUectvral Survey and Inventory Guidelines, and has determined that Building 23-517 is eligible for listing in the National Register of Historic Places (NRHP) under the Secretary's Significance Criteria A and C at the locai level of historic significance related to the era of nuclear testing; and WHEREAS, the NNSA/NFO has determined that the undertaking will constitute an adverse effect to the historic property Building 23-517, and has consulted with the Nevada Historic Preservation Officer (SHPO) pursuant to 36 C.F.R.
    [Show full text]
  • Utah Geological Association Publication 30.Pub
    Utah Geological Association Publication 30 - Pacific Section American Association of Petroleum Geologists Publication GB78 239 CENOZOIC EVOLUTION OF THE NORTHERN COLORADO RIVER EXTEN- SIONAL CORRIDOR, SOUTHERN NEVADA AND NORTHWEST ARIZONA JAMES E. FAULDS1, DANIEL L. FEUERBACH2*, CALVIN F. MILLER3, 4 AND EUGENE I. SMITH 1Nevada Bureau of Mines and Geology, University of Nevada, Mail Stop 178, Reno, NV 89557 2Department of Geology, University of Iowa, Iowa City, IA 52242 *Now at Exxon Mobil Development Company, 16825 Northchase Drive, Houston, TX 77060 3Department of Geology, Vanderbilt University, Nashville, TN 37235 4Department of Geoscience, University of Nevada, Las Vegas, NV 89154 ABSTRACT The northern Colorado River extensional corridor is a 70- to 100-km-wide region of moderately to highly extended crust along the eastern margin of the Basin and Range province in southern Nevada and northwestern Arizona. It has occupied a criti- cal structural position in the western Cordillera since Mesozoic time. In the Cretaceous through early Tertiary, it stood just east and north of major fold and thrust belts and also marked the northern end of a broad, gently (~15o) north-plunging uplift (Kingman arch) that extended southeastward through much of central Arizona. Mesozoic and Paleozoic strata were stripped from the arch by northeast-flowing streams. Peraluminous 65 to 73 Ma granites were emplaced at depths of at least 10 km and exposed in the core of the arch by earliest Miocene time. Calc-alkaline magmatism swept northward through the northern Colorado River extensional corridor during early to middle Miocene time, beginning at ~22 Ma in the south and ~12 Ma in the north.
    [Show full text]
  • Characterization of Hydraulic Properties Of
    Final Report for Award No. DE-FG03-94ER14462 1 Structural Heterogeneities and Paleo Fluid Flow in an Analog Sandstone Reservoir 2001-2004 By David Pollard and Atilla Aydin Department of Geological and Environmental Sciences Stanford University Stanford, California DOE, BES, and Chemical Sciences, Geosciences, and Biosciences Division Final Report for Award No. DE-FG03-94ER14462 2 TABLE OF CONTENTS TABLE OF CONTENTS ............................................................................................................................................2 EXECUTIVE SUMMARY.........................................................................................................................................3 INTRODUCTION AND BACKGROUND ...............................................................................................................4 GEOLOGIC AND STRUCTURAL SETTING .....................................................................................................................4 Regional Geology.................................................................................................................................................4 Principal Structural Elements of the Aztec Sandstone.........................................................................................5 SUMMARY RESULTS FROM THE GRANT PERIOD ........................................................................................6 1. CHEMICAL CHARACTERIZATION OF COLORED ALTERATION BANDS AND PALEO FLUID FLOW .................................6 2. CHARACTERIZING
    [Show full text]
  • Geological Society of America Bulletin
    Downloaded from gsabulletin.gsapubs.org on January 26, 2010 Geological Society of America Bulletin Sevier Orogenic Belt in Nevada and Utah RICHARD LEE ARMSTRONG Geological Society of America Bulletin 1968;79;429-458 doi: 10.1130/0016-7606(1968)79[429:SOBINA]2.0.CO;2 Email alerting services click www.gsapubs.org/cgi/alerts to receive free e-mail alerts when new articles cite this article Subscribe click www.gsapubs.org/subscriptions/ to subscribe to Geological Society of America Bulletin Permission request click http://www.geosociety.org/pubs/copyrt.htm#gsa to contact GSA Copyright not claimed on content prepared wholly by U.S. government employees within scope of their employment. Individual scientists are hereby granted permission, without fees or further requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in subsequent works and to make unlimited copies of items in GSA's journals for noncommercial use in classrooms to further education and science. This file may not be posted to any Web site, but authors may post the abstracts only of their articles on their own or their organization's Web site providing the posting includes a reference to the article's full citation. GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect official positions of the Society. Notes Copyright © 1968, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S.
    [Show full text]
  • Curriculum Vitae Page 1 of 7 Selly
    Curriculum Vitae Page 1 of 7 Dr. Tara Selly X-ray Microanalysis Core Assistant Director / Assistant Research Professor Department of Geological Sciences University of Missouri [email protected] EDUCATION: 2018 Ph.D. in Geologic Sciences with a minor in College Teaching, Department of Geological Sciences, University of Missouri, College of Arts and Sciences 2015 M.S. in Geologic Sciences, Department of Geological Sciences, University of Missouri, College of Arts and Sciences 2013 B.A. in Geology and Biology, Geology Department, Gustavus Adolphus College EMPLOYMENT HISTORY: 2019–Current Assistant Director, X-ray Microanalysis Core Facility; Department of Geological Sciences, University of Missouri 2019–Current Assistant Research Professor, Department of Geological Sciences, University of Missouri 2018–2019 Postdoctoral Researcher, Lab Manager of the X-ray Microanalysis Core Facility; Department of Geological Sciences, University of Missouri RESEARCH INTERESTS: • Implementing advanced microscopy techniques for data analysis • Taphonomy, actualistic studies, and experimental laboratory decay to analyze fossil preservation • Ediacaran and Cambrian taxonomy PUBLICATIONS, ABSTRACTS, AND PRESENTATIONS PUBLISHED ARTICLES: 9. Yang, B., Steiner, M., Schiffbauer, J.D., Selly, T., Wu, X., and Liu, P. [2020] Ultrastructure of Ediacaran cloudinids suggests diverse taphonomic histories and affinities with non- biomineralized annelids. Scientific Reports, 10: 1–12. doi: 10.1038/s41598-019-56317-x 8. Schiffbauer, J.D., Selly, T., Jacquet, S.M., Nelson, L.L., Strange, M.A., Cai, Y., and Smith, E.F. (2020). Discovery of bilaterian-type through-guts in cloudinomorphs from the terminal Ediacaran Period. Nature Communications, 11: 1–12. doi: 10.1038/s41467-019-13882-z 7. Lekakh, S., Zhang, X., Tucker, W., Lee, H., Selly, T., and Schiffbauer, J.D.
    [Show full text]